Cinematographic apparatus



Aug. 20, 1940. A. E. CARLSON CINEMATOGRAPHIC APPARTUS f Filed Nov. 22, 193s Patented Aug. 2o, 1940 UNITED STATES CINEMATOGRAPHIC APPARATUS Adolphe E. Carlson, Burbank, Calif., asslgnor to Technicolor Motion Picture Corporation, Los Angeles (Hollywood), Calif., a corporation of Maine Application November 22, 1938, Serial No. 241,725

2 Claims.

In the art of cinematography it is frequently desirable simultaneously to feed two films through the same film gate in face to face contact, that is front to front. back to back or front to back. For example, in color cinematography it is now common practice to employ a bipack camera adapted to feed two negatives through the same film gate with their emulsion sides inl contact with each other. For this purpose the two emulsions should be in intimate contact at the focal plane but there is such a pronounced tendency for trapped air to hold the films apart that much, difficulty has been encountered in attempting to keep both films in focus.

Objects of the present invention are to provide apparatus which avoids the aforesaid dimculty, which holds the films in intimate contact, which guides the film in uniform and constant relationship to the focal plane, which is simple fn construction and durable in use, and which involves no difficulty in threading the film through the apparatus.

According to the present invention the two films are separated just before they enter the v film gate so that they are brought into snug contact at the film gate along gradually converging paths thereby more effectively to counteract the tendency to trap thin pockets of air between the films. The film separator is preferably in the form of a pin mounted at one end adjacent corresponding edges of the two films and projecting edgewise of the film, the other end of the pin being unobstructed so that the films may be threaded with facility.

By lubricating the margins of the films they may be confined more closely and accurately as they pass through the film gate, thereby to maintain the films more uniformly and constantly in focus. According to this invention the lubricating device is associated with the aforesaid separator so that the separator serves not only the aforesaid purpose but also to press the films in contact with the lubricating surfaces.

For the purpose of illustration a typical embodiment of the invention is shown in the accompanying drawing in which Fig. 1 is a side elevation of a portion of a camera with the cover broken away and parts in section;

Fig. 21s a section on line 2-2 of Fig. 1;

Fig. 3 is a portion of Fig. 1 on a larger scale;

Fig. 4 is a detail view from the left of Fig. l;

Fig. 5 is a section on line-5 5 of Fig. 2; and

Fig. 6 is a section on line 6-6 of Fig. 1.

The particular embodiment of the invention chosen for the purpose of illustration is similar to that disclosed in the patent to J. A. Ball, et al. No. 2,072,091, granted March 2, 1937, to which reference is made for a description of those parts of the illustrated camera which are not directly 5 related to the subject-matter of the present invention. As described in the aforesaid patent the illustrated camera is designed to expose three films simultaneously from the same point of. View along the same optical axis, which is perpendicl0 ular tothe paper as indicated at I in Fig. 1 where the broken circle 2 indicates the general position of the single lens. Mounted behind the lens a prism unit 3 having an interior light-dividing surface which is not shown but which is located 15 in the plane indicated by the broken line 4 in Fig. 2., The light-dividing surface permits part of the light to be transmitted along the optical axis I to the film G while reflecting the rest. of the light to the left (Figs. 1 and 2) through the 20 aperture plate 5 to the bipack films B and R which are fed through the film gate 6 in face to face contact in the direction indicated by the arrow I in Fig. 1.

The films B and R. are fed step by step by 25 means of the film advancing mechanism 8 which may be of any suitable type, the films being accurately registered after they come to rest by means of the registering mechanism shown at 9 in Fig.

1. As shown in Figs. 1 and 6 the illustrated film- 30 feeding mechanism comprises an oscillatory armv 2l actuated by a pin 22 which projects eccentrically from the gear 23. The rear end of the arm 2| slides in the head of a pin 29 journaled at 30 and the forward end of the arm carries 35 film-feeding teeth 3| which extend through the slots 32 in the gate 6. The gear 23 is driven through the kinematic train comprising gear 24, shaft 25, worm gears 28 and 2l and shaft 28. The other film G is fed through similar mechanism 40 actuated through gears 33 and 34. The registering pin 9 is reciprocated back and forth by pin 35 eccentrically mounted on gear 24.

According to the present invention the films B and R are fed over a guide roll I I, thence oblique- 45 ly between lubricating pads I2 and I3, thence on opposite sides of a guide pin or separator I4 and .thence through the film gate. As shown in Fig. 2

counterclockwise .direction (Figs. i 3) to 'facilitate the threading of the lms. The guide pin Il is mounted at its inner end in the plate I9, the outer end ot the pin being free and una obstructed so that the lms may vbe readily threaded through the mechanism.

As the lms B and R feed obliquely through the lubricating device the margins of the illm are slightly lubricated by engagement with the pads I2 and i3. The pin it -serves the double purpose of causing the films to rub against the pads i2 and i3 and also to hold the lms apart so that l that this invention'includes all modiiications and equivalents which fall within the scopeof the appended claims.

I claim:

1. Cinematographic apparatus comprising a iilm gate having a ilm contacting entrance through which two iilmsv may be fed in face to face contact, film lubricating pads disposed on .opposite sides of the path of said illms, at a disaanwas tance therebetween considerably larger than the combined thickness of said illms. for lubricating themargins of said ims before they reach said gate, a support adjacent said iilms, andv means extending from said support between and edgewise of said iilms -dirctly in advance of said gate for separating said lms intermediate said pads and said entrance and pressing the separated lms into contact'with said pads, said separating means cooperating with said entrance to cause the illms to contact at the entrance along gradually converging paths.

2. Cinematographic apparatus comprising a lm gate having a film contacting entrance through-which two lms may be fed in face to face contact, lm lubricating pads disposed on opposite sides of the path of said lrns, at a distance therebetween considerably larger than the combined thickness of said ilms, for lubricating the margins oi said lms before they reach said gate, a support adjacent Acorresponding edges of said jlms, and a pin extending from said support between and edgewise of said lms directly in advance of said gate for separating said lms intermediate said pads and said entrance and pressing the separated .iilms into contact with said pads, said pin cooperating with said entrance to vcause the lms to contact at the entrance along gradually converging paths.

ADOLPHE E. CARLSON. 

